choke cap isn't moving the plate..

[scarecrow]

I went to go outside to adjust my choke since it's getting colder out, and I loosened the screws, turned the choke cap but it's not making the plate move at all. It's like turning the cap does nothing. The plate is adjusted so it's almost completely closed for some reason. Now my choke doesn't want to let off, and when it does its extremely slow. I have a Holley 670 by the way.

[grabbergreen84]

I think the aftermarket Holleys need a full 12V+ to the choke pull-off, whereas the original 4180 used a special Ford-style choke pull-off, which worked directly off of the alternator IIRC.

[JACook]

Aftermarket do need 12V, but turning the cap should still cause the choke plate to move. Sounds like it's
either not the correct cap for the carb, or the bimetal spring is not engaged properly.

The Motorcraft carbs use a bimetal spring with a kind of hook on the free end. The hook engages in a slot
in the arm inside the choke housing. The Holleys, including the 4180c, use a bimetal spring with a loop on
the end. The loop fits over the tang on the arm.

Also, the bimetal springs in Motorcraft and Holley choke covers are wound in opposite directions. Using the
wrong one will cause the choke to close as the spring heats up.